Method of refining distillates



- June 28, 1932. J FIELDS v I -1,36 4,719

' A METHOD OF REFINING DISTILLA TFIS Filed June 29, 1931 jnveiz Zor:

1757112 17. Fields.

Patented June 28-, 1932 JOHN D. FIELDS, OF LOS ANGELIS, CALIFORNIA Application filed June 29,

My present invention relates to a method of refining distillates, and more particularly pertains to a process for treating petroleum distillates such as gasoline, engine distillates,

kerosene, and kindred roducts, to remove certain impurities there r om.

While little is definitely known asto the components of distillates of the character above referred to, articularly as to the exact nature of the undesired impurities formed therein, it is generally recognized that some of such impurities are of resinous and gumm characterand include the olefin h drocar ons embracing mono-olefins, the dd? olefins or poly-olefins, and the acetylene isom ers of di-olefins; naphthenes; sulfur compounds; nitro en bases and acid compounds. It has heretof ore been a common practice to effect removal of the impurities, whatever their nature may be, by first treating the distillates with sulfuric or other acids; then water washing the acid treated distillates to remove the larger part of the acids that remain in the distillates after the slud e has been allowed to settle; washing the distlllates with an alkali wash embodying caustic soda,

sodium carbonate, or sodium plumbite, to effeet removal of naphthenes and to neutralize acids; then passing the distillatesfthrough a 1 filter of clay or diatomaceous earth, and

sometimes finally redistilling the distillates.

This practice results ina largewast e of the distillates under treatment caused in part by evaporation of the lighter fractions during handling thereof, and also results in the. loss of the removed 1m urities which byreason of the acid and afiali. treatments are rendered unfit for use and further entails the loss of the acids, a kalies, and filtering me- Furthermore,

' and octane number components of the distillates, which if reserved in the refined product would ren er it of higher grade and of superior quality particularly in the case of gasoline to be used as motor fuel as the ben-.

zol equivalent and octane number impart tothe product greatly desired anti-knock properties.

The primary object of the invention is to METHOD OF REFINING DISIILLATES 1931. semi mi. 54?,599.

e removed without destroying the benzol o5 equivalent and octane number constituents of the distillate, whereby such constituents are conserved so as to produce a high grade product. The action of the catalyst causes the saidmaterials to be coagulated or causes them to so react as tobecome insoluble in the menstruum, whereby the can be removed and separated from the oil distillate.

Another object is to effect recovery of the removed impurities in a form to permit of their utilization such for example as a component of fuel 011, and ,also in' the production of various substances of commercial value.

Another object of the invention is the pro-' vision of a method whereby the distillates ma be refined without material loss thereof an without substantial loss of the treating agent used thus enabling the roduction of a greater volume of the purifie product from a given volume of distillates under treatment than is obtained from-the usual process above referred to.

A further object is to provide a method of urifying' distillates which will attain the oregoing ob'ects in'an eflicacious manner .0 at low cost 0 operation, and wi h the aid of ap aratus of simple character. A

. highly important feature of the invention. resides in dispensin with the, use of reactive agents, alkalies, tering media and other substances which are commonl in the prior art, lost in the treatment of d stillates and con uently require replenishment at considerab e cost, thereby obviating the expense incident to the use of sucli substances and thus resulting in a process for refining distillates which is of great economic value.

My present invention whereby the foregoing objects are attained resides generally in subjecting the distillates containing the impurities, to the action of a catalytic agent of a character such that it will produce rapid condensation of the impurities and cause same to coagulate and separate from the distillates in a manner which will permit ready removal of the impurities; the process being carried into effect by maintaining distillates in juxtaposition with catalytic bodies within a chamber for such period of time and in such manner that the impurities to be removed will be caused to condense to form fiocculated masses which collect in part on the catalytic bodies for subsequent removal therefrom, and then delivering the distillates through a settling tank or other means for efiecting removal of such flocculated impurities as do not cling to the catalysts, and then redistilling the distillates where necessary to produce desired fractions.

The invention and the mode of accomplishing the objects and advantages above set forth, together with such other objects and advantages as may subsequently appear,

further resides in the steps and features hereinafter more fully described and claimed and illustrated by way of example in the accompanying drawing in which the figure is a diagrammatic view of a distillate refining apparatus and depicting the manner of carrying the invention into effect.

The apparatus as shown in the drawing embodies a series of catalyzer containing tanks A, B and C within which are mounted apertured catalyzer supports 2, 3 and 4 which are spaced from the bottoms of the tanks and are here shown as composed of wire netting. The spaces 5, 6 and 7 above the supports 2, 3 and 4 constitute catalyzing chambers within which are contained catalytic bodies D, E and F carried on the supports, which bodies are formed of an alkali metal, such as sodium, potassium or lithium.

The catalytic bodies are so shaped and so arranged within the catalyzing chambers as to permit the flow of distillates through said chambers yet cause the flowing. dis- I tillates to be deflected into numerous small streams which flow through the interstices between adjacent catalytic bodies in such manner that by the time a volume ofdistillates has passed through a catalyzing chamber the major portion thereof will have been brought into superficial contact with or in close proximity to a considerable area of the surfaces of the catalytic bodies. For this purpose the catalyzers may be shaped in the orm of spheres, blocks or bars. They are .placed within the tanks as by introducing them through man-holes with which the latter are equipped and which are normally tling chambers in which water and other sep-' arable foreign contents of the'distillates as well as a part of the reaction products thereof are collected and drawn off from time to time through drain-cocks 14, 15 and 16 fitted in drain pipes 17, 18 and 19- leading from the bottom portions of the tanks to suitable points of discharge. The tanks are fitted with depending tubular bafiies 20, 21 and 22 which lead downwardly from the upper ends of the tanks through the catalyzer supports and open in to the settling chambers beneath the supports in spaced relation to the lower ends of the tanks.

The distillates to be treated may be derived from petroleum in any desired manner, as by means of a still G from which the vapors are directed through a conduit 23 to a condenser H where the distillates are condensed. to a liq-aid form in the usual manner. The distillates while in liquid form and while at atmospheric temperature are directed through a conduit 24 into the upper portion of tank A, being delivered into the upper end portion of the tubular baflie 20 and directed downwardly through the latter into the lower portion of the tank from whence the distillates flow upwardly through the interstices between the catalytic bodies D to discharge through a conduit 25 leading from the upper end portion of the tank A.

Water content of the distillates settles out and collects in the lower portion of tank A beneath the'catalyzers as indicated at to be drawn off as required through the draincock 14, the water level being indicated by a gauge 26 with which the tank A is equipped.

The conduit 25 opens into the upper portion of the tubular bafile 21 in tank B to direct the distillates through the spaces between the catalyzers E in the latter in the manner describedwith reference to tank A; the distillates being delivered from tank B through a conduit 27 into the tubular baffle 22 in tank C where the distillates are directed through spaces between catalyzers F in tank C in a like manner and passed to discharge through a conduit 28 leading from the upper end of tank C. In this fashion the distillates-are directed through any suitable number of tanks as occasion may require to subject the [resinous and other gummy] impurities of the distillates to the action of the catalyzers a sufiici'ent length of time to efi'ect condensation of such impurities into a flocculent form; the duration of time being varied according to the character of the distillates under treatment.

In practice it has been found that maintaining the distillates in 'juxta osition with the catalyzers for a period of om three to five hours at ordinary atmospheric temperaseparable foreign matter as many accumulate in the settling chambers. The tank 3 is fitted with a gauge 28 toindicate water level in the settling chamber 12.

Such portions of the flocculated impurities as do not settle and remain in sus ension in the distillates may be removed rom the distillates by redistilling the latter in a still L to which the distillates are delivered from the end tank C through the conduit 29, or may, if desired, be recovered by filtration of the treated distillates in a usual manner.

The distillates after having been treated in the tanks are preferably redistilled, but are not necessarily so; thesubsequent treatment of the distillates depending on the character of the treated distillates and the results desired. For example, first run (or straight run) gasoline does not ordinarily require redistilling but in some cases may be benefited thereby. Where the treated distillates embrace light and heavy fractions they are redistilled to separate the distillates" into desired fractions such as distillate, and kerosene.

While the present method is applicable to the treatment of petroleum distillates of various fractions or combinations thereof, it is especially applicable to the treatment of distillates of low boiling point, that is distillates which pass off at temperatures up to approximately 500 degrees Fahrenheit, and may be distillates derived from heavy pegasoline, engine troleum oils by cracking. In fact the method is designed to be employed in the treatment of any hydrocarbons containing impurities which are subject to being removed as herein set forth by the action of alkali metal catalyzers.

The apparatus as here shown is designed for continuous operation that is for a continuous run until conditions necessitate a shut down, and is also designed to facilitate a cleaning out operation to effect recovery of the concentrated impurities as will presently be described, but manifestly any suitable apparatus may be employed to carry out .the process.

While I do not wish to bind myself to anyparticular theory of operation, nevertheless it seems proper to state that the alkali metal may act as a catalyst to produce a condensin reaction whereby certain sulfur compoun and/or other im- 3 products bein purities may condense to form products which are insoluble in the menstruum, these usually of a gummy or resinous or rub ery nature which coagulates.

In the course-of a protracted run of the distillates through the catalyzing chambers the catalyzers will become coated with a gummy resinous mass consisting of the impurities before referred to, which coating while not interfering with the catalytic action must be removed in order to obviate clogging of the apparatus and also to effect recovery of the substances constitutin such coating. This is accomplished by iscon- -tinuing fiowof the distillates through the tanks, draining the fluids-from the tanks,

then filling the tanks with a solvent of the separated. impurities. For this purpose,

benzol or benzene is used as a solvent to' which is added a quantity of alcohol for the purpose of activating the catalyzers. A volume of alcohol of from five to ten per cent of that of the benzol is ordinarily employed, but a somewhat smaller portion of alcohol may sometimes be used.

The coated catalyzers are thus maintained submerged in a benzol-alcohol bath a sufficient length of time to effect dissolving of the coating of impurities whereupon the bath is removed from the tanks with the dissolved impurities held in solution therein and is distilled in such manner as to effect separation and recovery of the benzol, alcohol and the previously dissolved I substances containedtherein.

By employing alcohol in the, benzol solvent an action is had on the alkali metal bodies such as to hasten the formation of the flocculent gummy resinous matter and lessens its tendency to cling to the surfaces of the bodies, and also renders the separation of the coating from the bodies more rapid and thorough. It is therefore desirable to subject the alkali metal bodies to an alcohol contain ing bath before initially employing them in the treatment of the distillates. Ordinarily the flow of the mixture of benzol and alcohol through the tanks A, B and C will only have to be continued for a very short time, until the deposited coagulated matter is removed, which leaves the surface of the sodium bright and clean, whereby the apparatus 1s ready for use in continuing the process of treating more of the petroleum dlstlllate.

After having thus washed the catalyzers with benzol containing a little alcohol and cleansed the tanks of the solvent, the apparatus (still containing the alkali metal catalytic agent in a reactivated state) is thereby left in readiness for another run of the distillates to be treated.

The removed impurities are of resinous sesses valuable qualities and may be employed in various uses, such for example as an added constituent to fuel oil.

- An important feature of the invention reat normal atmospheric pressures.

ll claim: 1. The method of removing impurities from petroleum distillates, consisting in subjecting such distillates in liquid condition to the catalytic action of a mass of, solid bodies of an alkali metal in the cold, for a suflicient period of time to effect coagulation of the bulk of the impurities, whereby some of the impurities become precipitated on the alkali metal, and separating the coagulated substances from the distillates, and separating the material deposited upon the alkali metal from said alkali metal by treatment with a solvent liquid, without causing appreciable chemical action of said impurities or oil upon said alkali metal catalyst, and repeating the cycle of operations.

2. The method of removing from petroleum distillates impurities contained in solu tion therein, consisting in maintaining a mass of solid bodies of alkali metal and the distillates in intimate juxtaposition, while at about normal atmospheric temperature, for several hours to effect coagulation of at least a major portion of the impurities in the oil treated, and effecting separation of the co agulated substances rom the distillates, removing the material deposited upon the surface of the alkali metal by treatment with a solvent, all without destroying any appreciable portion of the said alkali metal used, and treating a further quantity of such oil distillates with the alkali metal so cleaned.

3. The method of purifying petroleum distillates, consisting in effecting How of liquid distillates which are at normal atmospheric temperature, through the interstices between a mass of bodies of solid alkali metal, for a sufficient duration of time to cause impurities contained in the distillates to be subjected to the catalytic action of said bodies to become converted into a coagulated condition within the liquid, and efiecting separation of the coagulated impurities from the distillates, without destroying any substantial amount of the solid alkali metal, continuing said treatment until said alkali metal becomes coated with a layer of precipitated impurities, removing such layer to expose a clean surface ofthe alkali metal, and treating a further amount of petroleum distillate with said alkali metal, under like conditions.

4. The method of removing impurities on said bodies of alkali metal for subsequent removal therefrom, removing such impurities from the surface of said metal and re- .activating the metal by treatment with a composite solvent comprising benzol and alcohol, and treating a further amount ofsaid distillate with said alkali metal.

5. The method of treating a petroleum distillate to remove impurities held in solution therein, consisting in conveying the distillate between and among solid bodies of an alkali metal submerged in the distillate which is at normal atmospheric temperature, and thereby giving intimate and effective contact between the bodies of alkali metal and the substances in the distillate which are subject to coagulation, such actionbeing continued for a suflicient period of time tocause coagulation and separation of a part of the impurities from the distillate under treatment and to cause another part of the impurities to collect on the surface of said alkali metal and then effecting removal of the coagulated impurities from the distillate and separately from the surface of the alkali metal, all without destroying said alkali metal, and treating more-of said distillate with said alkali metal.

6. The method of removing impurities from a petroleum distillate, consisting in maintaining submerged within a stream of by cause a portion of the impurities to collect liquid petroleum distillate which is at normal atmospheric temperature, a mass of solid bodies of alkali metal, and which have previously been subjected to a wash with benzol containing not substantially over 10% of alcohol, and maintaining the liquid petroleum distillate and said mass of solid bodies in contact for a suflicient length of time to efiect catalytic coagulation of the impurities in the said petroleum distillate and to cause a portion of such coagulated impurities to accumulate on said solid bodies, and thereafter drawing off the treated petroleum distillate from said bodies and recovering the coagulated impurities therefrom, without destroying any appreciable portion of said alkali metal so employed.

7. The method of removing impurities from petroleum distillate, consisting in mainliquid petroleum distillate while at normal atmospheric temperature, a stationary mass of bodies of solid alkali metal, which has previously been subjected to a wash with benzol containing a small percentage only of alcohol, and maintaining contact of the \liquid petroleum distillate and said bodies of al- .taining submerged within a stream of the kali metal for a sufficient length of time to moval from said metallic catalytic bodies of the coagulated impurities accumulated thereeffect catalytic coagulation of the impurities in the distillate so as to cause one portion of such impurities .to accumulate on said bodies of alkali metal, and to efiect the flocculation of another portion of the coagulated impurities in the said stream of petroleum distillate, and separating the distillate from the coagulated impurities thus acted on, including separating the treated distillate from said alkali metal bodies and efl'ecting reof said flocculent impurities, separating the distillate from the coated alkali metal bodies,

all Without converting any appreciable proportion of said alkali metal into compounds thereof, treating the alkali metal so coated with impurities, with a solvent for the latter and then repeating the cycle of operations.

9. The method of removing and recovering resinous and other gummy substances from a petroleum distillate, which comprises placing many solid pieces of alkali metal in a flowing current of such liquid petroleum distillate while. at about normal atmospheric temperature, maintaining the said petroleum distillate and said pieces of alkali metal'in intimate contact with each other until the major part at least of the resinous and gum my substances have become coagulated, and a part thereof coated upon the said pieces of alkali metal, separating the distillate from the coated pieces of alkali metal, dissolving the coagulated impurities from the said pieces of alkali metal in a mixture of benzol with a minor percentage of alcohol, and distilling the benzol and alcohol to recover the dissolved substances therefrom, without converting any appreciable quantity of said alkali metal into chemical compounds thereof,' and thereafter repeating the cycle of opera tions.

10. In a method of removing impurities from a liquid petroleum distillate by a catalytic coagulation of the impurities, the step of contacting said distillate at about/ordinary atmospheric temperature with solid pieces of an alkali metal as a catalyzer which is substantially unafi'ected chemically by said impurities or distillate when in a water-free state, and thereafter cleaning and regenerating the said alkali metal catalyzer by subjecting the same to a wash with a mixture of benzol and only a minor'proportion of alcohol, and repeating the cycle of operations.

11. A process of purifying a liquid petroleumdistillate which does not contain any substantial proportion of water, which comprises flowing said liquid petroleum distillate through the interstices of a quiet mass of solid pieces of metallic sodium until the impurities in the oil have, at least in large part, been coagulated, one part of said coagulated impurities being deposited upon the surfaces of the metallic sodium and'another part of said coagulated impuritiesbeing car ried in. the oil, and before the interstices of said quiet mass of pieces of metallic sodium have been-entirely clogged up by said de-' posit on the sodium discontinuing the flow of said distillate, and then subjecting said quiet mass of solid pieces of sodium in situ to a wash with a mixture of benzol with about 5 to 10% of alcohol,- whereby-the metallic sodium is again rendered active, and repeating the cycle of operations. 7

12. A process of purifying a liquid petroleum distillate which does not contain any substantial proportion of water, which comprises flowing said liquid petroleum distillate through the interstices of a quiet mass of solid pieces of metallic alkali metal until the impuritiesin the oil have, at least in large part, been coagulated, one part of said coagulated impurities being deposited upon the surfaces of the metallic alkali metal and another part of said coagulated impurities being carried in the oil, and before the interstices of said quiet mass of pieces of metallic alkali metal have been entirely clogged up by said deposit on the alkali metal, discontinuing the flow of said distillate, and then subjecting said quietmass of solid pieces of alkali metal in situ to awash with a mixture of benzol with about 5 to 10% of alcohol, where-V by the metallic alkali metal is again rendered active, and repeating the cycle of operations.

13. A process of treating mineral oil distillatewhich comprises contacting such dis- .tillate with pieces of solid alkali metal, at

about normal atmospheric temperature and allowing contact of such metal with the oil distillate until the gummy impurities of said oil distillate are, inalarge part at least, coagulated and until a part of said coagulated impurities are deposited upon said alkali metal, without substantial chemical action of said impurities ,or oil, on said alkali metal, subjecting said so coated alkali metal to action of a mixture of benzol and alcohol, in which mixture the benzol is present in amount much greater than the amount of said alcohol, to dissolve said coating from the alkali metal and leave the alkali metal, and thereafter again treating more of the mineral oil distillate with said alkali metal.

M. A process which comprises contacting a mass of solid alkali metal, at very substantially below its melting point, with a large bulk of a etroleum oil distillate in the substantial absence of water, until said alkali metal becomes coated with a substantial layer of coagulated impurities, without substantial chemical action of said impurities or oil, on said alkali metal, then withdrawing said petroleum' oil distillate from contact with said alkali metal, and fioodingthe latter with a liquid which has a solvent action on the coatin ,and which acts to leave the surface of sand alkali metal in a highly active state, and thereafter repeating said cycle of operations.

15. A process which comprises contacting solid alkali metal with a mixture of several parts of benzol and one part of alcohol, at about normal atmospheric temperature, then contacting said alkali metal with pertoleum hydrocarbon oil, at about normal atmospheric temperature,'until said alkali metal comes coated with impurities coagulated upon the same from said oil, and thereafter repeating the said steps in succession. JOHN D. FIELDS. 

